top of page
  • Writer's pictureThe Brightonian Media (BulldogCyberNews)

A Woman’s Weapon: Poisoning Homicides of the 19th and 20th Century

by Marley Freitas

All fans of murder mystery know poison is a woman’s weapon. In the 19th to 20th century a common poison of the time was the arsenic compound arsenic trioxide. During this time arsenic was easily accessible and could be purchased as a rat poison as well as found in medication. Arsenic was also used in many day to day products like paint, wallpaper, dyes, toys, and glass. But to be fatal, arsenic would have to be consumed or exposed to in a large dose. This was where poison became a convenient weapon of choice for women. As women were expected to handle meals in their household one could easily poison her husband's or children’s food and they would be none the wiser. Of course murder weapons are not exclusive to any one gender, but poison is frequently characterized as a feminine weapon because poison avoids physical altercation and eliminates the mess that most other weapons would cause.

Arsenic was used as a homicidal agent as early as the middle ages. It was not until 1851 that an act was passed in the United Kingdom to regulate the sale of arsenic. But before this, arsenic was surprisingly accessible. Arsenic could be purchased at a local chemist for rat poison.

Scottish toxicologist and physician Robert Christison discovered that arsenic had a very slight sweet taste making it easy for arsenic to go unnoticed in food. Even the symptoms of arsenic poisoning were very similar to other common bugs passed around during this time leaving it unnoticed before it's too late. Some prime examples of female murders using arsenic as a weapon include Marie Lafarge, Mary Ann Cotton, and Amy Archer Gilligan.

The most famous part of Madame Lafarge’s case is her trial. Marie Fortuneè Cappelle was married against her will to Charles Lafarge and poisoned him with arsenic in a cake mailed to him while he was on a business trip in Paris. At this time arsenic poisoning was difficult to prove and the decomposition of Charles Lafarges body added to the incredibility, making the trial a fascinating story to follow. After many failed attempts by many doctors to prove Charles Lafarge had arsenic in his system the Marsh test was used. The Marsh test was invented by chemist John Marsh in 1836. This test includes mixing the potential poisoned matter with a zinc and acid creating a gas. This gas is then lit with a flame, and in the presence of arsenic a distinctive metallic film will be deposited. The Marsh test was useful in court as it could be demonstrated before a jury proving without a doubt that the matter contains arsenic. Although many attempts of the Marsh test had failed, famous toxicologist Mateu Orfila, who was specially trained to use the Marsh test, was able to prove there was arsenic in Charles Lafarge’s system. Marie Laarge was sentenced to life in prison, even with the evidence presented in court the verdict was controversial.

One of the most notorious and first serial killers of Britain was Mary Ann Cotton. After Mary Ann and her first husband William Mowbray lost four of their five children in 1856 to gastric fever Mowbray got life insurance for the surviving members of their family. In the 1960s Mowbray and three of their surviving children also passed from gastric fever. Mary Ann left her only living daughter with her mother and moved on. She then married George Ward. Less than a year after their marriage Ward died of gastric fever. But Mary Ann quickly married again in 1867 to James Robinson but he would not get a life insurance policy after four of his children died and eventually left Mary Ann. Mary Ann's next two male partners also died of fever and left her another child and more insurance money. Mary Ann had poisoned and murdered a total of 21 people. Mary got away with this for so long because no one even considered poison as the symptoms of arsenic mimicked gastric fever. Even if it had been suggested arsenic had been the cause of death of Mary Ann’s victims, arsenic was so common at this time it could have been written off as in something wallpaper of a room they frequented.

It was not until the death of Mary Ann’s step son were suspicions raised. Her trial began in 1873 after giving birth to her last child in prison. Although the wallpaper argument was made by Mary Ann’s lawyer the jury took only an hour to determine Mary Ann as guilty. Mary Ann Cotton hung for her crimes March 24, 1873.

One more especially devious murderer of this time Amy Archer-Gilligan. Amy married James Archer in 1896 and the couple worked as live-in caretakers for widower John Seymore. Seymour passed in 1904, Amy and James continued to rent out and house and care for elderly tenants. But the Seymore family sold the house in 1907 leading Amy and James to open the Archer Home for Aged People in Windsor. James died of kidney failure in 1910 leaving Amy to run the house on her own. Amy got along well with the people of Windsor and contributed to the community; her only suspicious behavior was the large amounts of arsenic she would purchase for the Archer home's alleged rat problems. In 1913 Amy remarried Michael Gilligan but he passed only 3 months into their marriage. But this was not the only suspicious death tied to Amy; 60 residents had died at the nursing home between 1907 and 1916. Forty-eight of these deaths occurred within 5 years. But finally the death of Franklin Andrews, a tenant of the Archer Home, raised some suspicion to the strange deaths of the Archer Home. After being seen in perfect health by witnesses Andrews tragically died the next day. Andrews’ sister found information about a $500 loan to Amy leading Andrews’ sister to suspect foul play. The authorities were contacted and Amy was arrested in 1916. Gillgian’s trial began in June 1917 and occurred over 4 weeks ending the the jury taking 4 hours to find Gilligan guilty.

It’s crazy to see how differently crimes were committed and trials were held in the 19th to 29th century compared to today’s world. Even though the motives of these women were mostly greed and not as poetically satisfying as a mystery novel you can’t help but be in awe at the real life mysteries unfolding before our eyes in real time. And slightly admire the cunning of these women despite their cruel motives.


Carlton, Genevieve. “The Story of Mary Ann Cotton, Britain’s First Serial Killer.” allthatsinteresting, June 23, 2021.

Barrel, Helen. “Poison Panic.” history-uk.

Blum, Deborah. “The Imperfect Myth of the Female Poisoner.” wired, January 28, 2013.

Connecticuthistory, “Windsor’s ‘Murder Factory’”, March 26, 2022.

Johnson, Ben. “Victorian Poisoners.” history-uk.

Little, Becky. “Arsenic and Old Lace: the Real Murder Behind the Classic Film.” History, October 25,2021.

Romeo, Jess. “The Arsenic Cake of Madame Lafarge.” daily.jstr, July 13, 2020.


bottom of page